If you have ever heard of nematodes, it has probably been in the context of gardening, where these little worm-like creatures are used to control slugs by the unpleasant process of crawling into the slug’s body through its various orifices, releasing a bacterium that kills the slug, and then growing and reproducing in the resultant broth, with their descendants crawling back out through the same orifices.
In fact, nematodes are ubiquitous, and not just in the soil. It has been said that if all the buildings on earth were to suddenly disappear, and only the nematodes remain, then the shapes of the buildings could be reconstructed from those of the ghostly films of nematodes that once covered them.
Be that as it may, nematodes are very useful to science for another reason. Uniquely among the animal phyla, each individual of any particular species of nematode has exactly the same number of cells, put together in exactly the same way.
This makes the nematode an ideal subject for study when it comes to the efforts of developmental biologists to understand just how multi-celled animals self-assemble, since the individuals of one generation after another will self-organize its cells in just the same way as other individuals. Some cells differentiate (i.e. change to perform different functions) while sitting in the some place. Others travel considerable distances. All of this was first studied and recorded by Sydney Brenner and his colleagues in the 1960s, using the nematode Caenorhabditis elegans. Transparent and about 1mm long, this little nematode, studied by many other workers since, has told us more about how multicellular organisms develop than any other species. And all due to a nice bit of lateral thinking by Sydney Brenner, who bet twenty years of his research life that this project would work – and won.
IMAGE: Wikimedia Commons